How close are the 'Vulcan'? Could it be darker where the others are?

Cool it with the phosphate fertilizer until you have a soil test done. Chances are you will find there is now plenty of it. Put on too much and a toxicity can occur, ones this happens removal and replacement of soil is about the only option.

I have the same problem with Anah.
I have it for three years, bought in early summer with no buds on and never saw a single bud forming.
Luscious 4x6' full, not leggy plant, but...no flowers.
It was moved last spring and I planted 'Persy Wiseman' in exactly the same hole where 'Anah' was. 'Percy' now have over 40 buds, but 'Anah' has no buds even in a new location.
Well, will be used as a very nice green screen in a back of the border.

I stopped the phosphate when I started getting blooms on the Vulcans. I know that too much of a good thing can be toxic and only used it a couple of years. It may be just a little more shady on the Anahs but not by much. I have a spot that came open due to a shrub being taken out and might move the Anahs there (or maybe just one of them since they're so large now) to see if a little brighter light might help. I was glad to see that somebody else had the same problem with them. I'd like to hear from somebody that has gotten them to bloom.

My Anah can take full sun here and flowers profusely.

My Anah Kruschke grows in full sun and is always covered with blooms.

Did it flower? It is almost 20 years ago jajaja. I have the same problem with mine now in 2014😏